Influence of Molecular Rigidity on Interfacial Ordering in Diphenyl-Based Polysiloxane Films

Journal Article · Mon Jan 01 00:00:00 EST 2007 · Polymer

DOI:https://doi.org/10.1016/j.polymer.2007.10.006· OSTI ID:959877

Evmenenko, G; Kewalramani, S; Dutta, P

Synchrotron X-ray reflectivity (XRR) shows significant differences between the ordering in thin films of diphenyl-based siloxane oligomers with single versus double backbones of -Si-O- repeating groups. We show that the more restricted conformational arrangement of twofold-skeleton molecules results in a higher degree of molecular ordering indicated by 2-2.5 times higher value of intensity of the corresponding Bragg peak in thin solid films of poly(phenylsilsesquioxane) than in films of poly(diphenylsiloxane), regardless of the solvent used for film casting. In both cases, the ordered molecules are located within 40-50 Angstroms of the substrate surface. The results indicate unambiguously that the chain stiffness of siloxanes governs the degree of ordering in the restricted geometry of the interfacial region.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: DE-AC02-98CH10886
• OSTI ID: 959877
• Report Number(s): BNL-82863-2009-JA; POLMAG; TRN: US1005818
• Journal Information: Polymer, Vol. 48, Issue 24; ISSN 0032-3861
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
43 PARTICLE ACCELERATORS
BRAGG CURVE
CASTING
CHAINS
FLEXIBILITY
GEOMETRY
REFLECTIVITY
SILOXANES
SOLVENTS
SUBSTRATES
SYNCHROTRONS
THIN FILMS
national synchrotron light source